import math
WIDTH = 800
HEIGHT = 800
lenth = 100
Dy = 400
x,hy = 400,200
ly = hy + 50 * math.sqrt(3)
Bx = x - 50
Cx = x + 50
def draw():
    screen.draw.line((Bx,ly),(Cx,ly),(200,0,0))
    screen.draw.line((x,hy),(Bx,ly),(0,200,0))
    screen.draw.line((x,hy),(Cx,ly),(0,0,200))